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Time to Shine

The 2013 SCU Solar Decathlon team builds on the University’s legacy

The 2013 Santa Clara University Solar Decathlon team is in its final push to bring home a first place finish. The team is currently at the site of the international competition in Irvine, where they are rebuilding Radiant House, SCU’s newest entry in the U.S. Department of Energy’s Solar Decathlon.

Twenty college teams from Arizona to Austria are competing to design, build, and operate the most cost-effective, energy-efficient, and attractive solar-powered house. The teams will show off their hard work at the Orange County Great Park in Irvine, Calif., Oct. 3 through 13.

This is the third time that a team from SCU has competed in the Solar Decathlon. In previous years, Santa Clara’s entries received impressive third-place awards, besting larger technical colleges and top-ranked universities from around the world.

“In 2007 the team focus was on engineering. In 2009, it was on design. This year, we’re shooting for the best of both worlds,” explained Jake Gallau, the student project manager for Radiant House. “Our solar house will be about 20 percent bigger than the last one and will be built for about two-thirds of the cost.” The frugal $300,000 construction budget will garner high marks from decathlon judges, who assign points in 10 competitive categories.

Beyond affordability, Radiant House has other attributes that set it apart from its predecessors, according to Gallau, who will graduate in June with a degree in mechanical engineering. He cited a number of advanced technological features throughout the structure, right up to the rooftop.

“In designing this year’s house, we made a conscious decision to innovate,” he explained. “We looked at technology that we liked and tried to find ways to improve it to meet our needs. We didn’t want to just use existing bells and whistles; our goal was to build a modern home that people would actually want to live in.”

Up on the roof

In searching for other ways to reduce material costs and apply effective technologies to their design, students found an all-in-one roof structure by Sunplanter with built-in solar panel rails. A passive cooling system below the panels prevents overheating, while the rails capture and divert heat from the warm air circulating below the panels. This pre-heated air is sent to Radiant House’s clothes dryer, which uses up to 20 percent less energy than a traditional dryer.

The solar panels are connected in a series, explained Gallau, and if a panel is underperforming, an energy optimization system creates a bypass option for that panel. This allows the photovoltaic roof array to operate at its full potential. “At any time, a resident can log into an account and see a graphical display with real-time energy output for every panel,” he said. “It’s one more user interface tied into the control system."

Blowing hot and cold

In most homes, ambient air is used to heat and cool interiors. SCU students designed their model with radiant panels that use hot water to heat the house and cold water to cool it. Developed by Messana Air-Ray Conditioning, the method creates a more uniform air flow without the usual blasts of air found in traditional systems. “A forced-air system dries you out,” said Gallau. “It may give you instant relief, but it’s not as comfortable as our system.” Student engineers say that not only is their water system highly efficient, it is also less expensive than standard HVAC options.

Banking on bamboo

Perhaps the most innovative design feature of Radiant House is its use of bamboo as a construction material throughout the entire building. Typically relegated to flooring and decking, bamboo has a much larger role in Radiant House. Raw, unprocessed (and therefore more sustainable) bamboo can be found in the house’s joists, stud walls, and shear walls. “It’s strong and lightweight, and the industry has spent the last 10 years trying to make it a structural building element,” said Gallau. “We found a way to do that; we’ve done the testing, submitted the paperwork, and matched all of the elements required by the building code.”

Normally the round shape of bamboo and its hollow culms, or stems, make the plant viable for forming “tiki hut-type structures” in tropical lands, but not for building much in other parts of the world, according to Gallau. Through a faculty member in SCU’s civil engineering department, the student team found a type of bamboo in Vietnam that makes the plant far more useful.

“It’s a particular strain of bamboo, smaller—about an inch around instead of three inches—and with a solid, not hollow culm,” Gallau explained. Because bamboo is both elegant and highly sustainable, it is usually integrated in some way within most solar house entries. But Gallau said Radiant House is the first to fully use the plant’s potential as a construction material. “With the type of bamboo we’re using, we can square off a large piece and make one-inch rods that can be woven together for a flat surface,” he explained. “It’s much less labor-intensive than chopping up chunks and gluing pieces together.”

Throughout the process of designing and building the 1,000-square-foot, net zero energy house, Gallau said three words have guided the effort: efficiency, elegance, and economy. During the past 18 months, about 200 undergraduate students, faculty, staff, community sponsors, and industry advisors have contributed in some way to the project.

Charles “Charlie” Hernandez, a construction manager for Plant Construction in San Francisco, is on the decathlon team’s advisory committee. He said the students’ work will be valuable experience in the field. “Learning and constructing leading-edge building technology at this early point in their lives will allow them to join Bay Area builders in the near future, engaging quickly to have an impact on the sustainable and innovated delivery of construction.” A board member for the SCU Bronco Builders Association, Hernandez said he’s enjoyed observing the students. “It’s been fun to watch Jake and his core team plan and implement a very detailed schedule while learning about real life challenges.”

Gallau heads a primary group of sub-team leaders in charge of everything from plumbing to public relations. He said 25 students were hired to work over the summer and many more labor on voluntarily. “Everyone,” he noted, “is in love with this project.”

Radiant House Fine Points

964-square-foot house featuring an open, modern design for sustainable California lifestyle

Native, drought-resistant landscaping surrounding the house

Sustainably sourced furnishings and unique, repurposed fixtures

House’s entire center module can be opened to the outside by pressing a button, increasing living and entertainment space

User-friendly control system with simple, large icons provides feedback on home energy use and suggestions for saving energy

Design incorporates an electric fueling station where a new, all-electric Nissan Leaf will be parked during the competition

SCU team promotes solar energy education in dozens of elementary school classrooms by using video conferencing to show youngsters how Radiant House is taking shape. See the last one here!